如何在 Lucene 5 中获取 Span Term Query 的匹配跨度? [英] How to get the matching spans of a Span Term Query in Lucene 5?

问题描述

在 Lucene 中，要获取一个术语周围的单词，建议使用 Span Queries.http://lucidworks.com 中有很好的演练/blog/accessing-words-around-a-positional-match-in-lucene/

In Lucene to get the words around a term it is advised to use Span Queries. There is good walkthrough in http://lucidworks.com/blog/accessing-words-around-a-positional-match-in-lucene/

应该使用 getSpans() 方法访问跨度.

The spans are supposed to be accessed using the getSpans() method.

SpanTermQuery fleeceQ = new SpanTermQuery(new Term("content", "fleece"));
Spans spans = fleeceQ.getSpans(searcher.getIndexReader());

然后在 Lucene 4 中，API 发生了变化，getSpans() 方法变得更加复杂，最后，在最新的 Lucene 版本 (5.3.0) 中，该方法被删除(显然移至 SpanWeight 类).

Then in Lucene 4 the API changed and the getSpans() method got more complex, and finally, in the latest Lucene release (5.3.0), this method was removed (apparently moved to the SpanWeight class).

那么，当前访问跨度项查询匹配的跨度的方式是什么?

So, which is the current way of accessing spans matched by a span term query?

推荐答案

方法如下.

LeafReader pseudoAtomicReader = SlowCompositeReaderWrapper.wrap(reader);
Term term = new Term("field", "fox");
SpanTermQuery spanTermQuery = new SpanTermQuery(term);
SpanWeight spanWeight = spanTermQuery.createWeight(is, false);
Spans spans = spanWeight.getSpans(pseudoAtomicReader.getContext(), Postings.POSITIONS);

Lucene 5.3 版中也不再支持通过 span.next() 对 span 进行迭代.要遍历跨度，您可以这样做

The support for iterating over the spans via span.next() is also gone in version 5.3 of Lucene. To iterate over the spans you can do

int nxtDoc = 0;
while((nxtDoc = spans.nextDoc()) != spans.NO_MORE_DOCS){
  System.out.println(spans.toString());
  int id = nxtDoc;
  System.out.println("doc_id="+id);
  Document doc = reader.document(id);
  System.out.println(doc.getField("field"));
  System.out.println(spans.nextStartPosition());
  System.out.println(spans.endPosition());
}

这篇关于如何在 Lucene 5 中获取 Span Term Query 的匹配跨度?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！